The present invention relates to apparatus for limiting the firing field of a barrel-type tubular weapon to a given target area during practice firing. In particular, it relates to apparatus for limiting the firing field of a mobile weapon, such as an armored cannon, mounted on a battle tank.
Firing field limiting devices are designed to limit the firing angle within which a weapon can be fired with respect to azimuth as well as elevation in order to prevent shots fired by the weapon from striking outside a predetermined target area. Limitation of the firing field to a given target area is necessary because, on the one hand, modern weapons employ long range ammunition and can be fired even when they are moving and, on the other hand, the locations available for practice firing usually extend over a relatively small area.
In the prior art devices of the above-mentioned type for use with the armored cannon of a battle tank, an instructor or supervisor controls the position of the barrel and authorizes firing, the instructor being accommodated either on a seat in the rear portion of the tank turret or at the commander's station. The permissible deviation of the barrel position from the target is marked by demarcation posts on the firing line or on the firing range. With the aid of these demarcation posts, the instructor controls the barrel position in azimuth and elevation, for example from the commander's station via the commander's periscope in the battle tank, and transmits a signal via a key to a fire unblocking device when the barrel is positioned within the given range.
These prior art firing field limiting devices are only marginally reliable because precise control of the position of the weapon is impossible. Further, a sudden change in the position of the barrel after the gun has been unblocked for firing might not be within the natural reaction time of the instructor. If the instructor is seated at the turret, he is subjected to very high stresses, such as firing noise, weather influences, dust, etc., and is particularly endangered when the weapon system malfunctions. If he is seated at the commander's station in the tank, this space is no longer available for training or test runs so that only restricted use can be made of the tank's fire guidance system. Also, if there is a defect in the fire guidance system which prevents the commander's periscope from following the weapon, stray shots could be fired which might hit far outside the target sector and have unpredictable consequences.
In another prior art firing field limiting device for a battle tank, a television camera is disposed in the beam path of an optical target finding device such as a target telescope, the picture from the television camera being transmitted via a radio path to the fire control center. An instructor, located in the fire control center, determines by means of the television picture whether the position of the armored cannon lies within a given range and, if this is the case, radios an unblocking signal to the fire unblocking device in the tank. This system has the same disadvantages as the previously described prior art devices due to the human reaction time of the instructor. Moreover, it is necessary to provide one monitor or instructor for every tank on the firing line as well as a separate radio transmission channel for each tank.
It is an object of the present invention to provide a reliable device for limiting the firing field of a weapon to a given target area during practice firing. It is a further object of the invention to provide a firing field limiting device which operates automatically without the intervention of an instructor or supervisor.